UVB-induced melanogenesis may be mediated through the MSH-receptor system.
UVB-induced melanogenesis may be mediated through the MSH-receptor system.
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DOI：
10.1016/0022-202x(89)90177-2
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发表时间：
1989-05
期刊：
影响因子：
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通讯作者：
J. L. Bolognia;Marilyn Murray;John M. Pawelek
中科院分区：
文献类型：
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作者：
J. L. Bolognia;Marilyn Murray;John M. Pawelek
紫外线B辐射(UVB)引起哺乳动物皮肤黑色素生成增加。调控这一过程的机制尚不清楚，尽管有充分的证据表明，产生黑色素的黑素细胞的数量有所增加。促黑激素(MSH)是一个多肽家族，通过与高亲和力受体相互作用增加黑素细胞的黑素含量。我们已经获得的证据表明，UVB对黑素生成的影响可能是通过增加黑素细胞上MSH受体的活性来实现的。首先，Cloudman S91小鼠黑色素瘤细胞暴露于中波紫外线后，24小时内125I-MSH与细胞的结合增加。在五个单独的实验中，中波紫外线照射的培养物显示MSH结合能力是未照射对照培养物(最佳剂量为10-20mJ/cm2)的2-10倍。其次，UVB和MSH在促进小鼠和豚鼠皮肤黑素合成方面相互增强。在同时接受UVB和MSH的豚鼠皮肤中，单独接受MSH或UVB的区域中，活性黑素细胞/mm~2比活性黑素细胞/mm~2的总和增加了5倍。我们的结果表明，UVB光导致皮肤黑素细胞上MSH受体活性增加，从而提高细胞对MSH的反应性。这一机制隐含着在UVB诱导的黑色素生成过程中将辐射能量转化为化学能的过程。
Ultraviolet B radiation (UVB) elicits an increase in melanin production in mammalian skin. The mechanisms regulating this process are not understood, although it is well documented that there is an increase in the number of melanin-producing melanocytes. The melanotropins (MSH) are a family of peptides that increase the melanin content of melanocytes through an interaction with high affinity receptors. We have obtained evidence that the effects of UVB on melanogenesis may be mediated through an increase in MSH receptor activity on melanocytes. First, exposure of Cloudman S91 mouse melanoma cells to UVB resulted in increased binding of125I-MSH to cells within 24 h. In five separate experiments, UVB-irradiated cultures displayed 2–10-fold increases in MSH binding capacity over that of unirradiated control cultures (optimum doses 10–20 mJ/cm2). Second, UVB and MSH potentiated one another in promoting cutaneous melanogenesis in both mice and guinea pigs. In the areas of guinea pig skin that received both UVB and MSH, there was a fivefold increase in active melanocytes/mm2over the sum of active melanocytes/mm2in areas receiving either MSH or UVB separately. Our results suggest that UVB light causes an increase in MSH receptor activity on cutaneous melanocytes, thus increasing cellular responsiveness to MSH. Implicit in this mechanism is a transduction of radiant energy into chemical energy during the process of UVB-induced melanogenesis.